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Browse Prior Art Database

Green Sheet Surface Porosity Measurement By Fluorescent Dye Absorption

IP.com Disclosure Number: IPCOM000048668D
Original Publication Date: 1982-Mar-01
Included in the Prior Art Database: 2005-Feb-09
Document File: 2 page(s) / 13K

Publishing Venue

IBM

Related People

Crowley, JI: AUTHOR [+2]

Abstract

To measure the porosity of a green sheet, it is dipped into an aqueous solution of fluorescent dye, washed with water, and dried. The amount of dye adsorbed into the surface of the sheet is determined by measuring the intensity of fluorescence from the sheet under suitable excitation. The measurement is made at numerous different positions across the sheet to assess point-to-point porosity variations and obtain an average value for the sheet as a whole.

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Green Sheet Surface Porosity Measurement By Fluorescent Dye Absorption

To measure the porosity of a green sheet, it is dipped into an aqueous solution of fluorescent dye, washed with water, and dried. The amount of dye adsorbed into the surface of the sheet is determined by measuring the intensity of fluorescence from the sheet under suitable excitation. The measurement is made at numerous different positions across the sheet to assess point-to-point porosity variations and obtain an average value for the sheet as a whole.

Dye Solution: The dye solution is prepared by dissolving 0.75 percent Rhodamine B (C.I. 45170) and 0.75 percent fluorad FC 95 (3M Chemical Division) in distilled water. After standing for a few hours or overnight, with agitation as required, the solution is filtered and is then ready for use.

Sheet Treatment: The solution is stored in a glass tank 25X25X 10 cm, with a glass panel as a top. Each sheet is dipped for 10 seconds to about two-thirds of its length in the red solution, leaving one-third undyed for the background fluorescence measurement. The sheets are immediately removed and thoroughly rinsed in running tap water at room temperature. Rubber gloves are used for all green sheet handling to minimize soiling or contamination of the sheets.

They are rinsed until no visible changes are taking place, usually 1 to 2 minutes, and are then blotted dry. The sheets are further dried in a vacuum chamber and allowed to equilibrate with air before fluorescence measurements are made.

Fluorescence Measurement: The sheet is fastened onto s special clip board to hold it flat and rigid. The holder is p...